An enterprise or business may subscribe to a variety of communication services provided by one or more service providers who operate owned or leased telecommunications equipment. The subscriber may be provided access to the public communications network by a local exchange carrier (LEC) which provides one or more dedicated lines to each subscriber from a switch. The traffic from multiple subscribers may be switched by the LEC to share a common resource according to statistical multiplexing techniques or some other process. Alternatively, a subscriber may be allocated a dedicated line, for example a T-1 resource, on a continuous basis rather than a switched basis.
The subscriber may obtain connectivity to the Internet by subscribing to an Internet service provided by an Internet service provider (ISP). The ISP may provide this Internet service with a port on a router operated by the ISP. The port on the router may be dedicated or reserved primarily or completely for the use of the subscriber. The subscriber connectivity to the Internet may be provided by a first communication link from the subscriber to the LEC switch and by a second communication link from the LEC switch to the port on the router. Alternatively, the subscriber connectivity to the Internet may be provided directly or indirectly by a single communication link from the subscriber to the port on the router. A router is an electronic device that provides connectivity between two networks and typically supports routing of data packets to other network nodes based on addresses embedded in the header of the data packets.
The communication services may be defined, at least in part, by a service level agreement (SLA) that may define a class of service, a bandwidth, and other key communication parameters. A SLA may also define service availability, time to identify the cause of a customer affecting malfunction, time to repair a customer affecting malfunction, service provisioning time, and other. A quality of service (QoS) and/or a class of service associated with the communication service may be implied by the SLA.
A communication service subscribed to by some enterprises is the virtual private network (VPN) communication service. VPNs may be used by enterprises to communicate confidentially within the enterprise, between different sites, offices, or campuses, over a public communications network. VPN traffic can be carried over a public network infrastructure, such as the Internet, on top of standard protocols, or over a service provider's private network with a defined SLA between the subscriber and the service provider. A VPN can send a variety of communications traffic including data, voice, video, or a combination of these and other traffic. In some cases, VPNs may be provided based on multi-protocol label switching (MPLS) techniques.